Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody. Caudal-related homeobox 2 (CDX-2) is an intestine specific transcription factor protein regulating the differentiation and proliferation of intestinal epithelial cells. The expression of CDX-2 protein is found in oesophageal and gastrointestinal adenocarcinomas in addition to gastrointestinal neuroendocrine tumours.